De Rosa SLX - can you date it please.

Hi,

I know this is De Rosa SLX(prestige, professional, etc called by many names, but I will stick to SLX for now).

I hear anything between '89 to '92, and I'd like to know for sure.

The cockpit is Cinelli Campione del mondo and stem is un marked except ‘Made in Italy’ Looks like Cinelli E1....